Heating and Cooling› Thermostats, Housings and Fillers

Motorcraft

190 Degree Engine Coolant Thermostat Assembly

$35.82

SKU: RT1254

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INSTALL DIFFICULTY
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Easy — 1–2 hours

Overview

The Motorcraft RT1254 is an engine coolant thermostat assembly designed to regulate engine temperature. It operates at 190 degrees Fahrenheit and is included with the lower housing, water manifold, thermostat housing, and thermostat unit assembly.

This thermostat is specified for various Ford applications, including 6.2L, 5.4L, and 6.8L engines. It fits 1999-2007 Super Duty models, as well as 1997-1999 LD vehicles with 4.6L and 5.4L engines. Additionally, it is compatible with F150 New Style models from 2004-2008 and Mark LT. It also fits F150 models from 1997-2003 and the Heritage 2004 (4.6L, 5.4L).
Show original supplier description
The Motorcraft RT1254 is a genuine OEM engine coolant thermostat assembly engineered to maintain optimal engine operating temperatures for a range of Ford vehicles. This thermostat assembly includes the necessary components such as the lower housing, water manifold, thermostat housing, and the thermostat unit itself, facilitating a complete replacement. It is designed to operate at a precise 190-degree Fahrenheit temperature, crucial for efficient engine performance and emissions control. The RT1254 is compatible with a wide array of Ford engines and model years. Applications include 6.2L, 5.4L, and 6.8L engines. It fits 1999-2007 Super Duty trucks, as well as 1997-1999 LD vehicles equipped with 4.6L and 5.4L engines. Furthermore, it is suitable for F150 New Style models manufactured between 2004 and 2008, and the Mark LT. The F150 models from 1997-2003 and the Heritage 2004 (specifically with 4.6L and 5.4L engines) are also covered by this thermostat's fitment.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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Specifications

BrandMotorcraft
Part NumberRT1254
CategoryHeating and Cooling
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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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